This weekend, Americans everywhere will celebrate the Memorial Day holiday. With this start of the summer comes the worry that idle time will become the devil’s workshop for so many young people out of school. Adding to that predicament is the fact that this summer, unlike any since the Great Depression, unemployment will be at an all-time high. The result in big cities across the country? Crime will increase too, experts say.

Every year around this time, we broach this subject. Why does crime go up as the weather warms up each summer? Students are out of school, more people are outside, and more people are active. This seems to lead to a general increase in crime — a trend for decades.

The problem in 2010 is that this long hot summer will be a long hot jobless summer. So, according to law enforcement officials, many cities — already overburdened with criminal activity — will see much more than just the ordinary juvenile crimes or petty acts.

“You’ll see a lot of property crimes, and in the course of those crimes being committed, violence, even murders, if a victim resists,” said Richard Pennington, a law enforcement expert who was chief of the Atlanta and New Orleans police departments, after more than two decades on the Washington, D.C., force.

There are volumes of academic research on the subject to show the correlation between unemployment and higher crime. However, Pennington says his research comes from defendants firsthand, many of whom were picked up in summer months, who reveal that they were stealing to survive, because they did not have or could not find a job.

“When we catch them they would say the reason they broke into a house, is because they had to feed their family or themselves,” Pennington said.

An expansive study by experts at the Ohio State University shows that low wages and unemployment make less-educated men, particularly, more likely to turn to crime.

“Public officials can put more cops on the beat, pass tougher sentencing laws, and take other steps to reduce crime, but there are limits to how much these can do,” said Bruce Weinberg, co-author of the study and associate professor of economics at the Ohio State University.

“We found that a bad labor market has a profound impact on the crime rates,” Weinberg said.

By June, there will be a new wave of recent high school graduates who are not college bound, who need work, but cannot find it—a notion that particularly hits African-Americans in large urban centers. In fact, the national unemployment rate for black teens is 37 percent — the highest of any group, according to the Bureau of Labor Statistics.

According the U.S. Labor Department, in April, the metropolitan unemployment rate in Detroit was a staggering 15.5 percent. Orlando was at 12.1 percent, Chicago at 11.3 percent, Cleveland at 10.1 percent, with Atlanta at 10.4 percent. The figures are likely much higher if you consider just the core inner city, not the outlying counties that make up the metro stats.

“If the unemployment rate is 10 and 12 percent, you can comfortably say that in the black community it is double that, and even higher for black males in certain urban environments,” said Waldo E. Johnson Jr., associate professor of social work at the University of Chicago’s School of Social Service Administration.

“We used to help kids get jobs for summer through the mayor’s office, other government-sponsored summer-jobs programs, but many of those are long gone,” said Johnson. “And even the summer jobs at fast-food restaurants are far and few between, because now young people are competing with older adults and seniors for those jobs.”

While cities brace for the uptick in property crimes this summer, Pennington says bank robberies are likely to increase too. During his last few years at the Atlanta Police Dept., he says bank robberies in the metro Atlanta area increased nearly 30 percent, and most of the robbers were unemployed.

In the current economic downturn, cities are finding more questions than answers in solving what has become a precarious cycle of maintaining safety. Every uniformed officer a commander pulls from the street to investigate a crime is one less patrol car roaming the streets to help prevent crime.

“As crime goes up, most of the cities are not hiring additional officers,” said Pennington. “The workload increases, and police have to start doing more with less, and departments become strained and drained.”

Officials in the White House and the Treasury Department claim the U.S. economy has turned the corner. However, the unemployment numbers show that Washington’s excitement to declare an economic recovery has yet to trickle down to urban America —especially in predominantly black and brown communities.

Law enforcement officials in cities across the nation aren’t seeing the turnaround. Instead, they’re bracing for a long, hot, jobless summer.